Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations, the description must carry the full behavioral burden. It only says 'Fast credit balance' and does not disclose whether the operation is read-only, what permissions are required, whether the balance is live or cached, or what happens on failure. The 'fast' adjective adds minor performance context but little behavioral substance.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is a single front-loaded sentence with no redundant clauses. It is appropriately concise for a simple tool, though the word 'Fast' is mild marketing rather than essential instruction.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a low-complexity tool with one fully described optional parameter and no nested objects, the description is minimally adequate. However, with no annotations and no output schema, it leaves the agent without information about return format or key behavioral expectations.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, and the single optional parameter is fully documented in the schema. The description adds no parameter semantics, so the baseline of 3 applies.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description names a specific resource (credit balance for the account) and implies a fast retrieval operation. It is clear enough to understand what the tool does, but it does not explicitly distinguish itself from sibling tools such as autowhisper_status.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

There is no guidance on when to use this tool versus alternatives, no stated prerequisites, and no exclusions. The agent is left to infer that it should call this when a credit balance is needed.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.